Articles, Blog

5 Things Your Nails Can Say About Your Health

August 13, 2019

Fingernails and toenails, they’re not just for decoration. They protect your fingers and toes and help you pick up tiny things, like splinters or that piece of spinach stuck between your teeth after lunch. And they can also tell you a lot about your health. Nails are collections of dead cells that grow from a root called a Matrix hidden just beneath your cuticle, the lighter crescent shaped area at the base. The matrix constantly makes new cells called Plate Cells, and each layer pushes the old, dead plate cells out of the cuticle. When nails start to grow differently or even change color, it usually means that there is something wrong with the matrix or with the surrounding tissue. So by working backward, you can often figure out what’s doing the interfering, and in the process maybe learn something about what’s going on in your own body. Beau’s Lines, for example, are horizontal ripples on the surface of the nail. They look like little waves, and they form when the matrix stops producing new cells for a while. When the matrix starts making new cells again, they push the nail out as usual, but there is an indentation marking the spot where it stopped, kind of like a tree ring. And there’s a reason why the matrix would’ve hit the pause button. Probably, it wasn’t getting enough nutrients from the blood stream. Usually, that means the person has an infection or some other kind of serious illness. That’s why people who have high fevers for a while, often develop Beau’s lines a month or two after- -wards. Pitted nails are another potential matrix issue, where the nails surfaces have indentations that look like very small pot holes. The pits are linked to skin disorders, like Psoriasis and Eczema, which can cause inflammation of the matrix. An inflamed matrix produced new plate cells unevenly, so you end up with depressions on the nail surface. Nails can also change color, something you’ve probably noticed if you’ve studied your nails on a cold day, and realized they were blue. Generally, that means that your extremities aren’t receiving enough oxygen. Blood with low oxygen is darker and reflects light differently through your skin making your nails look blueish. It could just be your body reacting to cold by constricting your blood vessels, but a person whose blood isn’t receiving enough oxygen could have a respiratory illness, like asthma or emphysema. Blue nails can also be a sign of Raynaud’s Disease. A disorder marked by spasms in a person’s blood vessels that narrow them. The narrowing reduces blood flow to the extremities, so they get blue nails. Now blue nails, it not actually the nail changing color, it’s the bed underneath it. But nails can also turn yellow, and that’s actually the nail changing color, this can happen for a lot of different reasons. In most cases, it’s cause by a fungal infection known as Onychomycosis. Yeast or mold sets up shop within the actual nail plate, turning it yellow. It doesn’t smell to good either. Other times, the yellow nails means something more serious, like Yellow Nail Syndrome, which doesn’t sound super serious, but it happens when the matrix does produce new plate cells but very slowly, so they pile up and create a thicker yellow-ish nail plate. But like Beau’s Lines, Yellow Nail Syndrome is caused by something else. It could be a chronic respiratory disease, which would reduce the nail’s oxygen supply and slow growth. Or it could be sign of an issue with the Lymphatic system, which distributes protein rich fluid throughout the body. Usually, that issue is cancer or aids. A black or brown streak in a nail can also be super serious, or nothing at all. In some people that streak can signal Subungual Melanoma, a form of skin cancer that affects the nail bed, which is the skin underneath the nail plate. Melanoma often changes the color of the skin, including the skin under nails. But the streak also might be harmless, if you have a darker complexion it’s completely normal. So it could be something, or it could be nothing. Which is why of you’re worried about the color or the look of your nails, here’s a tip. Don’t get all your medical advice from the internet! These changes can mean more than one thing, so talk to a real doctor before jumping to any conclusions. We are not a real doctor. Thanks for watching this episode of SciShow, which was brought to you by our patrons on Patreon, who give us money so that we can do this, which is really nice. If you want to help support this show, you can go to and do not forget, if you want to get smarter with us, to go to and subscribe.


  • Reply Mr. Raleigh D. November 17, 2017 at 4:05 am

    The Matrix has you.

  • Reply TimboGuddaVille November 17, 2017 at 5:11 am

    A black cat walked by.. and then another one just like it .. CHECK ITS FINGERNAILS

  • Reply Olivia Cagle November 19, 2017 at 12:19 am

    What if my nails are clear

  • Reply E Shark November 25, 2017 at 10:21 pm

    Phew I have a line on my nail will it be cancer will it not you'll find out if I'm in heaven

  • Reply Supreme November 25, 2017 at 11:25 pm

    These racist white study's of the black race always pop up.

  • Reply Agent Mothman November 26, 2017 at 2:01 pm

    The only thing thing I learned from this is that I'm dying cause I have horizontal lines across my nails. Way to help my anxiety, bucko.

  • Reply E Shark November 27, 2017 at 7:21 pm

    after i watched this video i'm now getting my nail removed because it has cancer i'm siroius i cant spell sireous

  • Reply 3p1ks December 8, 2017 at 2:47 am

    hmm, nails can't talk tho.

  • Reply Sharjeel Zahid December 9, 2017 at 7:34 am

    I subscribed!

  • Reply Leandro Costa December 15, 2017 at 1:57 pm

    "We are not a real doctor" lol

  • Reply Alexander Wu December 16, 2017 at 7:10 pm

    What does it mean when one of your cuticles disappears?

  • Reply Weltkrieg December 16, 2017 at 8:17 pm

    Jokes on you, I bite my nails!

  • Reply Kiddy Cringe December 22, 2017 at 10:33 pm

    Tbh, nails look ugly and are kinda lame, WHY CAN'T WE HAVE CLAWS INSTEAD!?

  • Reply مبشری معمدی December 26, 2017 at 8:58 am

    👌👌👌👌👌👌so good

  • Reply Sabrina Mei January 3, 2018 at 4:26 pm

    orrrr if you're simplynailogical yellow nails=wearing nail polish all the time

  • Reply Zachary den Boer January 6, 2018 at 12:23 pm

    "more important things like.. not dying"
    i beg to differ

  • Reply Asma Asma January 12, 2018 at 7:13 pm

    So yellow nails are not ok christen has been lying 😱😱

  • Reply Niels Pausma January 16, 2018 at 8:46 pm

    What about vertical ridges along your nails?

  • Reply RaceToNowhere January 23, 2018 at 8:13 am

    Yeah, I probably have cancer. The explosive kind.

  • Reply Vivia Martin January 26, 2018 at 9:15 pm

    My mom smokes and idk if she gas cancer or not but she has yellow nails 😥😢

  • Reply King Hip-O January 28, 2018 at 7:02 am

    When your hand is bigger than your face, you may have cancer.

  • Reply Ks 412 January 28, 2018 at 12:21 pm

    What if i have a vertical ridges on my left big toenail but all the other nails are find & my right foot also? But its just one ? & its kinda yellow at the tip i havent painted my nails a dark color since last year maybe sep or oct.

  • Reply J J January 29, 2018 at 9:29 pm

    My toenails grow incorrectly, causing constant ingrown toenail on the big toes. After several fixes at the GP, I was sent to have my toes cut open, nail bed removed on one side, and treated with (iirc) Hydrochloric acid, now they grow normally. Just thought that might be interesting.

  • Reply Reversed February 3, 2018 at 9:03 am

    That dark streak scared me before he mentioned that it's pretty common in people with darker completions. I mean, I'll still mention it to my doctor. But, I'm less nervous

  • Reply Surux Strawde February 5, 2018 at 1:01 am

    Not a real doctor, but certainly helpful.

  • Reply AB Z February 10, 2018 at 10:13 pm

    I've had beau's lines for years.

  • Reply jumpsteadywill February 12, 2018 at 8:13 pm

    Truer words have never been spoken…"Don't get all your medical advice from the internet!", but some is apparently okay…BTW, the internet says in no uncertain terms that everything that you are showing symptoms for is cancer, and certain death…so I would argue that no advice should come from the net…just cat videos and baby pictures…

  • Reply Want some Spaghetti! February 17, 2018 at 4:40 pm

    Who else checked their nails to find out if somethings wrong.

  • Reply LoL-O-Mat 1000 March 7, 2018 at 1:07 pm

    Really? No one in your Team has a PhD?

  • Reply Ninjamantis March 8, 2018 at 9:52 pm

    I know a person that has completely white nails, i'm still curious about it and drs don't care enough to answer questions like that they just tell you you're self examining

  • Reply Goos March 10, 2018 at 10:25 am

    I don't have cuticles on my fingers.

  • Reply IronPump89 March 18, 2018 at 5:32 pm

    thanks, really nailed this video

  • Reply Ella Vesper March 19, 2018 at 7:41 am

    I have very small brown stripes on 2 of my nails so i don't know that is this harmless or bad??

  • Reply blk bbw March 19, 2018 at 1:30 pm

    "Suck my ridges" 😏

  • Reply Falcony 100 March 22, 2018 at 8:02 pm


  • Reply Crystal Animations April 6, 2018 at 8:11 pm

    One dislike came from Cristine because they talked about yellow nails and their important diseases they come from. I’m sorry HoloQueen 💿💿💿

  • Reply Sajan B April 11, 2018 at 3:46 pm

    Why does the internet have to worry me so much aaahh

  • Reply Alex Hickey April 18, 2018 at 4:51 pm

    I have a white line going from the base of my thumb nail to the tip. Wtf is wrong with me

  • Reply High Overlord Snarffie Beagle April 21, 2018 at 12:19 am

    so the thumbnail for the video showed white lines in you nail and you didn't say anything about white lines in your nail once in the video?
    my left big toe has ripples and has since I smashed it really bad years ago at work, guess it's just weird now

  • Reply Amber Blyledge April 27, 2018 at 6:46 am

    I have very minor beau's lines because a few weeks ago I had constapatipn bad enough that I vomited what food I put in. So for a week after it started moving, I had to be very careful how much I put in. Horses also get those lines.

  • Reply oopsy444 April 27, 2018 at 8:30 pm

    Quickly looks at nails and stares at screen

  • Reply Mozi iOS April 29, 2018 at 10:50 am

    gg life

  • Reply Mahek Patel May 5, 2018 at 1:39 am

    What are the verticle brown lines on my nails ?

  • Reply Diogofrn May 8, 2018 at 8:34 pm

    i like the fact sci show tells viewers not to believe everything on the internet. kudos

  • Reply lj033 May 21, 2018 at 9:54 am

    What about small vertical ridges??

  • Reply Yellow Pikachu May 29, 2018 at 12:56 am

    I am gonna remove my nails

  • Reply Joey Barela May 29, 2018 at 7:12 pm

    My dad uses a razor blade to cut his nails since his are so thick… if he uses a nail cutter it breaks… I don't know what to tell him now.

  • Reply Aditya Mohapatra June 5, 2018 at 2:40 pm

    Thanks man

  • Reply Matthew Topping June 25, 2018 at 1:44 pm

    What does it mean when your nails are clear?

  • Reply Dunk61 August 1, 2018 at 7:55 pm

    Me, looking at my bloody, half-eaten nail: yikes…

  • Reply 2241RYAN August 6, 2018 at 3:32 pm

    My nails are pink AF ! Doc just told me that I've a very rich blood ! Is it true ? Anyone with pinkish nails ?

  • Reply HAMBUGAH CHEESEBUGAH August 8, 2018 at 11:16 am

    My other friends
    Has like short nails idk
    Mine is like normal nails idk pls explain

  • Reply JP August 18, 2018 at 3:19 pm

    Your finger nails tell a lot about your health. For example, not having them means you could be suffering from a serious case of pissing off captain Levi.

  • Reply Mae Pasta August 21, 2018 at 12:42 pm

    Well I must be dying. 😆 I have dips all in my nails.

  • Reply error53ish August 22, 2018 at 7:27 pm

    All that and you didn't talk about the white spots that can sometimes form in nails? sigh
    As far as I have been told… it is when your body has an excess of calcium.

  • Reply Jeff Dowell August 28, 2018 at 5:03 pm


  • Reply Jeff Dowell August 28, 2018 at 5:05 pm

    From the moment you're born you're all dying

  • Reply The Sparten Gamer September 10, 2018 at 7:32 pm

    I am Mexican and have a weird black streak on my pinky

  • Reply Chris September 10, 2018 at 8:40 pm

    What about those white spots on your nails !

  • Reply Danger Darth September 12, 2018 at 1:21 pm

    Yellow nails can also be caused by frequent painting your nails, and is common in nail polish models, even if they use a base coat. So I'd double down on the notion that you shouldn't get all your medical info from the internet. Still interesting.

    Now tell me why my nails frequently tear and seem to shred! TELL ME!! 🤬😭😉

  • Reply • JINX October 13, 2018 at 8:01 pm

    I male and my fingernails are transparent

  • Reply Iron Vanguard October 24, 2018 at 9:37 am

    Any nail biters here?

  • Reply Emajasmine October 27, 2018 at 4:13 am

    What if your nails are almost transparent and clear??

  • Reply LOGAN DAVIS December 1, 2018 at 5:16 pm

    Isn't subungual melanoma what bob marley died of?

  • Reply rumble fish December 2, 2018 at 6:46 am

    yellow nails = smoking

  • Reply Tegan December 8, 2018 at 1:45 pm

    I have eczema and my nails are fine skskskks.

  • Reply Candy Essex January 1, 2019 at 6:06 am

    My nails are clear

  • Reply Kenmore Chalfant January 20, 2019 at 7:00 pm

    3:30 been on a binge of your videos – makes me sad every time you say "don't get medical advice from the internet" – I and many others can't afford to go to the doctor. Go America! :/

  • Reply Kevinzhw Zhang wang January 22, 2019 at 1:02 am

    Can I also develop beau lines from pressure from too small shoes?

  • Reply Romeu Capela sa February 10, 2019 at 1:43 pm

    So we can breakout of the matrix

  • Reply Binozia - Tech February 15, 2019 at 8:39 am

    I have two cut my nails every 2 weeks they grow super insanely fast I can notice my nails growing every 2 days in fact I’m going to cut them now

  • Reply Paul McMullan February 15, 2019 at 1:36 pm

    You forgot to mention white spots on the nails which is fluoridosis or fluoride poisoning, cause by fluoride in drinking water.

  • Reply Rika5589 February 20, 2019 at 4:33 pm

    I really love how you always make sure to tell people to see an actual doctor. It's sad that people do try to take medical advice from the internet. Great information, as always though! Thank you! Never knew how the nails got all those abnormalities. (I knew they did and why, just not how)

  • Reply D Ldez February 24, 2019 at 4:58 pm

    What about when they are frail??

  • Reply AngelTheVoo February 25, 2019 at 1:26 pm

    my nails grow about 1/4 of an inch every month


  • Reply Abbieq11 March 11, 2019 at 12:22 am

    If you a sad because you have a skin issue, even your nails have depression(s)

  • Reply Abbieq11 March 11, 2019 at 12:24 am

    Hank are not a real doctor just so you know

  • Reply Võ Thái Sơn March 16, 2019 at 6:22 pm

    So like, Neo from The Matrix.

  • Reply Lauren Animates March 23, 2019 at 5:07 am


  • Reply starkeclipse March 24, 2019 at 9:46 pm

    And yet, you didn't mention the lost common nail item: vertical lines of not Al color in the nail bed. Most people have some, some people have lots or more pronounced ridges. So what's that all about?

  • Reply Jennifer Springhorn March 24, 2019 at 9:50 pm

    You forgot to mention longitudinal ridges and splitting/ flaking nails. Oh well, as you said don't get all your info from the internet.

  • Reply William Hardway March 25, 2019 at 1:26 am

    Guessing that it's sxurvy

  • Reply William Hardway March 25, 2019 at 1:26 am

    A lack of nutrients

  • Reply Wanda Richardson March 25, 2019 at 5:30 pm

    I have noticed that smokers have yellow nails too.
    Thank you for sharing✌💛☺

  • Reply _.ani4ka._ March 25, 2019 at 5:53 pm

    2:35 Cristine is triggered

  • Reply Juliana Person March 27, 2019 at 4:07 am

    What about when I get vertical ridges in my nails? Or when they get super brittle for a few months and then harden up again without any me doing anything different?

  • Reply Alice Flemming March 29, 2019 at 6:47 pm

    Dont worry if your nails are yellow if you wear a lot of nail polish. Wearing nail polish can turn the nails yellow

  • Reply KnightsWithoutATable April 16, 2019 at 10:06 pm

    No mention of zinc spots?

  • Reply Zanium April 17, 2019 at 6:23 am


  • Reply Chuzzlepuff Puffchuzzle April 17, 2019 at 4:39 pm

    "Yoshikage Kira subscribed"

  • Reply GodTierBunny April 19, 2019 at 7:25 pm

    So the beau line explains what happened when i got a strange fungal infection or something but what explains that i still have pits in my nails to this day. Is it cause the infevtion disrupted the nail matrix? This was like 2-5 ish years ago now

  • Reply Samrocket132 Fitsjerols May 15, 2019 at 12:18 am

    My nails are very thin like I can bend it nails down anyone else?

  • Reply Suman Saini May 17, 2019 at 4:56 pm

    What about those white streak on nails

  • Reply Bernard Shrewsbury May 26, 2019 at 1:42 am

    What about vertical ridges?

  • Reply Altaj Virani May 26, 2019 at 3:11 pm

    Day before yesterday, i.e on 24th May, 2019, I noticed some 2-3 small unusual black (or brown: difficult to differentiate) horizontal lines on my index finger of left hand, and on my right hand thumb, too. Is it a thing to worry about? I swear to God I freaked out after I read about this on the internet (which said it could be melanoma or splinter hemorrhage).
    I'm definitely going to consult a dermatologist about this.
    Please reply if you have any information about this, or you have yourself experienced this…..

  • Reply hereticpariah 6/66 May 29, 2019 at 9:54 pm


  • Reply ReineDeLaSeine14 June 2, 2019 at 5:08 am

    I have Beau’s lines and have had Raynaud’s for a long time.

  • Reply Common daily things June 15, 2019 at 7:31 pm

    Hey we are a new channel help us grow for quality content thNk you

  • Reply The Wild Dinkus! July 24, 2019 at 6:50 am

    My nails get white spots

  • Reply Killerboy 666 August 8, 2019 at 7:47 pm

    The most important thing said in the video is "we are not doctor"

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